Parvovirus infection is transmitted readily through direct contact with the feces and vomit of other infected animals, and indirectly through contact with surfaces contaminated with feces or vomit. Dogs may continue to pass the virus in their feces for up to 3 weeks following infection.
Once Parvovirus is ingested, it sets up house in the lymph nodes of the throat and begins to replicate. Viral particles are released into the bloodstream and attack rapidly dividing cells - especially those in the bone marrow, lymphoid tissue (where immune cells develop) and the digestive tract. Damage to the intestinal cells results in malabsorption, nausea and vomiting. Membranes in the gastrointestinal tract become damaged and intestinal bleeding may occur resulting in blood and mucus in the feces.
Puppies 6-20 weeks old are most susceptible to infection, because maternal antibodies obtained in the mother's milk have decreased in the puppy's body, and antibody levels from vaccination have not yet fully developed. The incubation period ranges from 3-8 days with passage of virus beginning somewhere around day 3, even though symptoms of infection may not yet have presented. Symptoms include vomiting, loss of appetite, loss of thirst, depression, abdominal pain and severe diarrhea. Dehydration occurs rapidly due to vomiting and the refusal to drink - extreme dehydration can lead to death.
Mortality rates can be as high as 48%, and the virus is readily stable in the environment, so that transmission of the virus may continue even after your pet recovers. Parvovirus is resistant to a number of commonly used disinfectants, and may survive for a period of time on contaminated surfaces. The virus has been around for approximately 20 years and is well entrenched in the environment - yards, parks and households. In addition, Parvovirus has a relatively small infectious dose, is excreted in large numbers in the feces of infected dogs, regardless of whether they have mild or severe infection, and continues to be excreted for a few weeks following infection.
A vaccine is available and vaccination is the best way to prevent infection in your pet. Vaccine can be given to pups as young as 5 weeks and should be given annually after initial vaccination.
Although you cannot rid the environment of the virus, a dilution of household bleach (1:30) is an effective disinfectant and thorough cleansing of all areas that infected pets may have been in contact with is essential to limiting spread. Although we humans do not become ill ourselves, we are important vectors of disease - we can spread the infection to healthy dogs on our contaminated hands, clothing, footwear and bedding. Floors and carpets are also surfaces through which your pet can become infected. Thorough cleansing should include the human environment as well as the canine environment - I don't know about your dog, but mine were never too choosy about what they licked or ate. Don't forget your pet's food and water bowls!
Judy Arbique - I graduated from Medical Laboratory Technology training in 1979 and since then obtained advanced recognition in clinical microbiology from ...
